Autonomous driving assistance systems (such as adaptive cruise control and lane-keeping systems, for example) do not perform optimally at all times. The operating efficiencies of such systems may vary with such factors as the environmental conditions under which the systems are operating, system component malfunctions, etc. Users unfamiliar with such systems are not always aware when the system is not operating at full efficiency, or why the system is not operating at full efficiency, or what factors affect operational efficiency of the system. Thus, when a system fails unexpectedly or operates, but fails to operate as expected, a vehicle user may lose confidence in the system. It would be beneficial to have a method and system which constantly informs the user of changes in the operating efficiency of autonomous driving assistance systems, and also informs the user as to why a system may not be functioning at full efficiency.